MOSCOW, May 3. /TASS/. Russian Foreign Minister Sergey Lavrov have talked by telephone with the chairman of the Organization for Security and Co-operation in Europe (OSCE), Ivica Dacic, following reports of Ukraine’s government forces using large-calibre artillery to shell the self-proclaimed Donetsk People’s Republic, the Foreign Ministry said in a statement on its Facebook page on Sunday.

Lavrov "has strongly urged him [Dacic] to use his authority so that the OSCE special monitoring mission to Ukraine demands that Kiev should immediately stop the blatant violation of the Minsk agreements", the statement said, adding that Dacic had promised to take all necessary measures.

According to the self-proclaimed republic’s Defence Ministry, forces loyal to Kiev on Saturday evening opened fire with heavy weapons on positions of the self-defence forces around the villages of Spartak, Peski and Yasinovataya, Donetsk airport and Donetsk’s northern districts.

The reports said that units of the Ukrainian military stationed near the village of Avdeyevka were using the NATO-standard 155mm calibre weapons, in violation of the Minsk agreements.

A February 12 peace deal struck in Minsk, Belarus, by leaders of Russia, Ukraine, Germany and France envisaged a ceasefire between Ukrainian forces and people’s militias starting from February 15.

This was to be followed by withdrawal of heavy weapons from the line of military engagement by at least 15 kilometres (9 miles), prisoner release and agreement for international observers to monitor the truce.

Withdrawal was due to start no later than the second day after the truce came into effect, for completion within two weeks.

Buffer zones were to be established of at least 50 kilometres (30 miles) for artillery of 100mm calibre or more, 70 kilometres for multiple rocket launch systems and 140 kilometres for the heaviest rockets and missiles.